import java.awt.*;
import java.awt.event.*;

public class TankClient extends Frame {
    public static final int GAME_WIDTH = 800; public static final int GAME_HEIGHT = 600;

    Tank myTank = new Tank(50, 50);

    //这是一张虚拟图片
    Image offScreenImage = null;

    //paint这个方法不需要被调用，一旦要被重画的时会被自动 调用
    public void paint(Graphics g) { myTank.draw(g);
    }

    public void update(Graphics g) {
        if(offScreenImage == null) {
            offScreenImage = this.createImage(GAME_WIDTH,
                    GAME_HEIGHT);
        }


//拿到这个图片的画笔
        Graphics gOffScreen = offScreenImage.getGraphics();

        Color c = gOffScreen.getColor(); gOffScreen.setColor(Color.GREEN); gOffScreen.fillRect(0, 0, GAME_WIDTH, GAME_HEIGHT); gOffScreen.setColor(c);
        print(gOffScreen); g.drawImage(offScreenImage, 0, 0, null);
    }

    public void launchFrame() { this.setLocation(300, 50); this.setSize(GAME_WIDTH, GAME_HEIGHT); this.setTitle("TankWar"); addWindowListener(new WindowAdapter() {
        public void windowClosing(WindowEvent e) { System.exit(0);
        }
    });
        this.setResizable(false); this.setBackground(Color.GREEN);

        this.addKeyListener(new KeyMonitor()); setVisible(true);
        new Thread(new PaintThread()).start();
    }

    public static void main(String[] args) { TankClient tc = new TankClient(); tc.launchFrame();
    }

    private class PaintThread implements Runnable {

        public void run() {
            while(true) { repaint(); try {
                Thread.sleep(50);
            } catch (InterruptedException e) { e.printStackTrace();


            }
            }
        }

    }

    private class KeyMonitor extends KeyAdapter {
        public void keyPressed(KeyEvent e) { myTank.KyePressed(e);
        }

    }

}
